In the case where a monitoring camera is used as an auxiliary means for performing work using a construction machine safely and smoothly, it is necessary to provide a display for showing the image of the camera in a driver's cabin (for example, Japanese Patent Provisional Publication No. 2002-294762).
On the other hand, for an indicator of the construction machine, especially a hydraulic excavator, not only fuel and engine cooling water but also the temperature of hydraulic oil for driving the excavator must be monitored, and these measurement values are shown on a gage or a liquid crystal display of the indicator.
However, the space of the driver's cabin is limited, so that a problem arises in that a display for showing camera images provided separately from the gage and the indicator obstructs the front field of vision.
Also, even in the case where alarm information is shown on a separate monitor for monitoring the equipment information, a problem arises in that it is difficult for the operator to become aware of the alarm information when he/she is paying attention to the display for camera.
Accordingly, Japanese Patent Provisional Publication No. 2002-371594 has disclosed a configuration in which switching from a first mode for showing an image from a rear monitoring camera on a single monitor screen to a second mode for showing a vehicle body state on the monitor screen and vice versa can be performed, and this switching operation is performed by the operation of a running operation means, by which the monitor screen is used in common.
However, conventionally, the rear monitoring camera has been operated by the operation of a running lever, and a method for monitoring the directions other than the rear has not been developed, so that the camera has poor flexibility.
Also, the camera has been fixed, and the movement of photographing position has not been thought, which poses a drawback in that the monitoring area is limited.
Patent Document 1: Japanese Patent Provisional Publication No. 2002-371594 Refer to FIG. 4